The 63-year-old leader, in power for nearly 12 years, also said she hoped to appoint equal numbers of male and female ministers from her conservative party if she wins a fourth term, though she could not speak for possible coalition partners.

"The worst has been avoided," Tsipras said after flying over the disaster zone northeast of Athens by helicopter, adding that about 3,700 acres (1,500 hectares) of forest and scrubland had been ravaged.

"Poland has become for the United States Army the centre of gravity for everything that we're doing in terms of deterrence," General Ben Hodges, commander of US ground forces in Europe, told reporters in Warsaw.